The present invention relates generally to a technique which, on the basis of sequentially-progressing performance information of music, automatically arranges in real time an automatic accompaniment performed together with the performance information.
In the conventionally-known automatic accompaniment techniques, such as the one disclosed in Japanese Patent Application Laid-open Publication No. 2012-203216, a multiplicity of sets of accompaniment style data (automatic accompaniment data) are prestored for a plurality of musical genres or categories, and in response to a user selecting a desired one of the sets of accompaniment style data and a desired performance tempo, an accompaniment pattern based on the selected set of accompaniment style data is automatically reproduced at the selected performance tempo. If the user itself executes a melody performance on a keyboard or the like during the reproduction of the accompaniment pattern, an ensemble of the melody performance and automatic accompaniment can be executed.
However, for an accompaniment pattern having tone pitch elements, such as a chord and/or an arpeggio, the conventionally-known automatic accompaniment techniques are not designed to change tone generation timings of individual notes constituting the accompaniment pattern, although they are designed to change, in accordance with chords identified in real time, tone pitches of accompaniment notes (tones) to be sounded. Thus, in an ensemble of a user's performance and an automatic accompaniment, it is not possible to match a rhythmic feel (accent) of the automatic accompaniment to that of the user's performance, which would result in the inconvenience that only an inflexible ensemble is executable. Further, although it might be possible to execute an ensemble matching the rhythmic feel (accent) of the user's performance by selecting in advance an accompaniment pattern matching as closely as possible the rhythmic feel (accent) of the user's performance, it is not easy to select such an appropriate accompaniment pattern from among a multiplicity of accompaniment patterns.